Effect of corn silage hybrid on dry matter yield, nutrient composition, invitro digestion, intake by dairy heifers, and milk production by dairy cows

Three corn hybrids, Mycogen TMF94, Cargill F337 (which contains a brown mid rib trait), and Pioneer 3861 were compared in a plot trial, an intake trial , and a lactation trial. In the plot trial, the three corn hybrids were pla nted in replicated 15.2 x 385-m plots. Mycogen TMF94 and Cargill F337 had l ower yields of dry matter (DM), higher concentrations of neutral detergent fiber, and higher in vitro true DM disappearance compared with Pioneer 3861 . Mycogen TMF94 had a higher yield of DM than Cargill F337 despite having a lower plant population. However, Cargill F337 had a higher in vitro true D M disappearance than Mycogen TMF94. In the intake trial, six individually p enned Holstein heifers were blocked and assigned randomly to one of three t otal mixed rations containing 79% (DM basis) Mycogen TMF94, Cargill F337, o r Pioneer 3861 corn silages in replicated 3 x 3 Latin squares. Heifers fed the Pioneer 3861-based TMR had lower DMI than heifers fed Mycogen TMF94 and Cargill F337-based TMR. In the lactation trial, 75 midlactation Holstein c ows were blocked and assigned randomly to one of three total mixed rations containing 31% (DM basis) Mycogen TMF94, Cargill F337, or Pioneer 3861 corn silages used in the intake trial. Milk production was highest for cows fed Cargill F337-based total mixed rations. It is concluded from this study th at Mycogen TMF94 was higher yielding, but less digestible, and resulted in lower milk production by lactating cows than Cargill F337. In addition, Myc ogen TMF94 had higher in vitro true DM disappearance, and similar DM yield and milk production by lactating cows when compared with Pioneer 3861.